Java code

Java code

Use a Java code node to run Java that you write yourself. Connect its EXEC input and output to choose when it runs and which nodes run after it.

Add inputs and outputs

Drop a link anywhere on the node to add a slot for it:

• Drag from another node's output and drop it on the Java code node. The node adds an input with that output's type and connects it. The input is named after the output, such as player for getPlayer.
• Drag from another node's input and drop it on the node to add a matching output.
• While you drag, the node shows + input or + output if it can add a slot. If it already has an unconnected input of the same type, or an output of the same type, the link connects to that slot instead.

EXEC links and REF inputs connect as usual.

To add a slot from the menu:

1. Open the node's menu and select Add input… or Add output….
2. Type to filter the Java types, and choose one. Common types come first. For a type that isn't listed, such as an array, type its full name and choose it at the top of the list.
3. Accept the suggested name, or enter a Java name without spaces or Java keywords.

Each name must be unique across the node's inputs and outputs. To rename a slot, right-click it and select Rename…. Renaming also changes the name everywhere it appears in your code as a whole word, except after a .. This includes text inside string literals, so check the code afterwards. To remove a slot, right-click it and select Remove Slot.

Inputs and outputs are local variables inside your code. Inputs are final, so you can read them but cannot assign a different value to them. Assign values to output variables to pass them to connected nodes. Unconnected inputs and outputs start as false for boolean, 0 for other primitive types, or null for class and array types.

Edit the code

Double-click the node, or select Edit code… from its menu. Enter Java statements in the multiline prompt. The node previews the first four lines.

Use full class names, such as java.lang.String or org.bukkit.entity.Player, in declarations and code. Do not add import lines. A Java compiler error in your code points to this node in the build errors.

A return; stops the node immediately. It skips copying output variables to the connected slots and skips the nodes after it.

Log a greeting when a player joins

1. Add a PlayerJoinEvent node and a Java code node.

2. Drag the event's getPlayer output onto the Java code node. It adds an input named player with type org.bukkit.entity.Player.

3. Select Add output…, choose String, and accept or enter the name greeting.

4. Connect the event's EXEC output to the code node's EXEC input.

5. Open Edit code… and enter this statement:

   greeting = "Hi " + player.getName();

Add a ConsoleLog node. Connect the code node's EXEC output to its EXEC input, and greeting to its value input. When a player joins, the server console logs a greeting with that player's name.

Import a snippet with Java code

Importing a snippet with Java code nodes shows a warning and a preview of up to 10 lines from each code node. These nodes run whatever code they contain on your server. Only select Add snippet if you trust where it came from. Select Cancel to leave the snippet out of your graph.